I just realize the Gripper Bot provided by the Ring It Up! Virtual World only supports encoders for the base drive motors but not the wrist, arm or the gripper. I am teaching our students doing PID control on the arm so that it can hold and maintain arm height. Obviously, without the encoder for the arm motor, this cannot be done. Is there any plan to add encoder support for at least the arm motor?Thanks.

Fri Oct 05, 2012 5:28 pm

JohnWatson

Site Admin

Joined: Thu May 24, 2012 12:15 pmPosts: 672

Re: Ring It Up Gripper bot has no arm encoder

At this time there is no encoder support for the wrists/arms/grippers in the Ring It Up! Virtual World. It is something, however, that we are actively working on and hope to have out soon.

We actually have big plans for the Sack Attack and Ring It Up virtual worlds!

Our initial infrastructure let us control a limited number of motors and encoders (3 and 2, respectively). We did a minor update to support additional motors for those games, and now we're working on a more substantial update to enable the full number of motors, encoders, and sensors supported by the VEX and NXT+TETRIX platforms. We expect to have new versions of ROBOTC and the competitions with that support later this month or the beginning of the next.

A little longer term, we're also starting to research two additional big improvements:1) Support for multiple players to compete head-to-head. This would be done over an Internet or a network connection.2) The ability for students to build their own robots in Maya or Blender, and then import them into our worlds.

We're excited about the direction that we're taking with these worlds. I hope you'll continue to offer suggestions and feedback.

I hope part of the plan is to add a gyro sensor to the Ring It Up! robots. Currently, they have a compass sensor. Compass sensor has issues if we want to use it to do PID controlled turns. The problem arises when the turn crosses "North" so the value will either jump from a low value (e.g. 5) to a high value (e.g. 358) when turning left or from a high value to a low value when turning right. PID control will go crazy and turn the wrong way. To remedy this problem, we had to write a separate compass module that will periodically monitor the compass value and keep track of the "accumulated heading" instead of absolute heading (i.e. when crossing north, we either subtract 360 or add 360 to the accumulated heading). We managed to make the compass work for our PID controlled turn but it certainly would be nice to have a gyro instead. Also, if it's not too much to ask, we would like to see the field with an IR beacon and the robot with TWO IR seeker sensors. We would like to experiment with binocular triangulation.I have been using the Virtual World as a class room tool to teach the students on RobotC programming. With a room full of students, I don't have to give each one an NXT robot when doing exercises. They would just write their code and test it with Virtual World. But for this to work, the robot must have more sensors so that I can cover different topics such as PID control on the arm and navigation by triangulation etc. I know that NXT has a limit of 4 sensor ports, one being used for the Tetrix motor controllers so there can only be 3 sensors at the max. Is there any plan to support Sensor MUX in the virtual world? That would be a wonderful news to us.Thank you for the great product.

Wed Oct 10, 2012 1:34 pm

jbflot

Site Admin

Joined: Tue May 15, 2007 9:02 amPosts: 406

Re: Ring It Up Gripper bot has no arm encoder

This is exactly the kind of feedback that we're looking for. Having suggestions with the reasoning behind it helps us evaluate and prioritize the information. The good news is that just about everything you've brought up is something we're at least considering.

We think that the Compass is great in the themed worlds for having an absolute heading when traversing a more open space. In our worlds that are more simulation based, like the competitions, we're planning on implementing the Gyro. Half of the reason is exactly what you described in your post; the other half is that the real-world sensors aren't always the most dependable, so they're not used by many competition teams. Our big focus at the moment is updating the infrastructure to allow all motors to have encoders, and to allow the full number of sensors used - the inclusion of the gyro will come out after.

With the two IR sensors, we're working toward this, albeit indirectly. Our eventual goal is for the user to be able to choose from any combination of sensors that we support (a list we're planning to grow).

We've definitely acknowledged the weakness of having only three sensors (excluding encoders) and discussed the Sensor MUX as a possible solution. It's a bigger development than it may seem at face value due to the MUX being I2C messaging heavy, and we'd have to build all of that capability into our emulator. As much as we'd love to allow teams to have more sensors, we probably won't have that capability this competition season.

That's great new. Has it released yet? I downloaded the latest RVW from http://www.robotc.net/ftc and it seems it is still the old one.

Sat Oct 27, 2012 4:56 am

rcahoon

Site Admin

Joined: Tue Oct 09, 2012 10:34 amPosts: 192

Re: Ring It Up Gripper bot has no arm encoder

As mentioned in the blog post, this update has included some architecture changes to the way RobotC interfaces with the Virtual Worlds that allow the number of motors and sensors on the virtual robots to only be limited by the robot platform (i.e. 3+4 for NXT, more for Tetrix and Vex). We're working on the last steps in integrating those changes, and should have a release out in very early November (which, luckily isn't too far away )

As mentioned in the blog post, this update has included some architecture changes to the way RobotC interfaces with the Virtual Worlds that allow the number of motors and sensors on the virtual robots to only be limited by the robot platform (i.e. 3+4 for NXT, more for Tetrix and Vex). We're working on the last steps in integrating those changes, and should have a release out in very early November (which, luckily isn't too far away )

Now that RobotC 3.54 is released, I downloaded the Ring It Up Level Pack again but it seems it was still the old one. So when will the new one be released? As time approaches to regional competitions, the benefit of Virtual World is diminishing because by now we should hopefully have a fully functional robot. It may still be useful to do some quick tests on a strategy when the students have no access to the real robot but since the robot in the Virtual World is different from the real robot, it may not be practical to use the Virtual World at this point.

Sun Nov 04, 2012 1:48 pm

rcahoon

Site Admin

Joined: Tue Oct 09, 2012 10:34 amPosts: 192

Re: Ring It Up Gripper bot has no arm encoder

MHTS wrote:

Now that RobotC 3.54 is released, I downloaded the Ring It Up Level Pack again but it seems it was still the old one. So when will the new one be released? As time approaches to regional competitions, the benefit of Virtual World is diminishing because by now we should hopefully have a fully functional robot. It may still be useful to do some quick tests on a strategy when the students have no access to the real robot but since the robot in the Virtual World is different from the real robot, it may not be practical to use the Virtual World at this point.

Hope you've seen the new release by this point. We're in a process of continual improvement and try to get new functionality out to the community as quickly as we can while still maintaining our level of product quality. Now that the support for additional sensors and motors has been integrated, it will be a feature in our future releases as well, so if it's too late to use in this competition, look forward to using it in your next season.

No, I haven't seen the new release. What do I need to download to get the "new release"? I downloaded the RingItUp World but "binary compare" showed that it was the same binary as I downloaded before, so there isn't any change.

Tue Nov 13, 2012 3:15 pm

rcahoon

Site Admin

Joined: Tue Oct 09, 2012 10:34 amPosts: 192

Re: Ring It Up Gripper bot has no arm encoder

I installed from http://www.robotc.net/files/RVWLevelPack_FTC_RingItUp_150.exe (the installation currently linked from robotc.net) and the new features are present and working for me. When you launch the Ring It Up virtual world, what version number is reported in the lower-right corner of the splash screen? It should be 1.5.0. If this installation doesn't work for you, my best suggestion would be to try uninstalling the Ring It Up through the Control Panel before installing the new one.

I just installed the new Ring It Up field and changed the code to use the gyro and it totally broke my code.

Routine 1: Timed drive - The robot is supposed to drive in a straight line for 7 seconds at 100% power then turn left for 1.4 seconds (approx. 90 degrees) and back up for 5 seconds. The old Ring It Up drives very straight but the new one drifts to the left.

I have a periodic task that integrates the gyro reading to keep track of the robot heading. So just for the fun of it, I displayed the heading on the LCD screen while it was doing timed drive and the number was showing zero at first which is expected. But when it starts to turn left, I was expecting it to give me approx. -90. Instead it gave me a big negative number (in the thousands). Then even when the robot has stopped, the heading was still integrating very fast with bigger and bigger negative number. Note the same gyro integration code has been used in real robots for years without any issue. So the virtual world environment somehow broke it. Question: does nPgmTime work correctly in Virtual World? Because the gyro module is using nPgmTime to do time integration. If time is incorrect, the integration won't work.

Routine 2: Drive straight ahead until sonar detects an obstacle at 25cm. Sometimes, this works perfectly, sometimes the robot doesn't stop. I haven't had the time to check into why yet.

Routine 3: The robot is suppose to do a very complex driving pattern. This code was working perfectly when it was using the compass code but with the gyro, it is totally broken. The first action was supposed to drive forward for 100 inches butthe robot starts turning round and round in place. Again, I haven't had time to look into why yet. But the code was working with the compass in the previous field.

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